/Engine/Plugins/Importers/USDImporter/Source/GeometryCacheUSD/Public/GeometryCacheTrackUSD.h
Note: Bounds may be sampled at a different rate than the matrixes above so they have separate sample indexes to cache.
const bool
virtual const bool UpdateBoundsData ( const float Time, const bool bLooping, const bool bIsPlayingBackward, int32 & InOutBoundsSampleIndex, FBox & OutBounds )